Device and method for generating user notifications associated with tasks that are pending completion

ABSTRACT

A device and method for generating user notifications associated with tasks that are pending completion on a mobile device. When additional input is required from a user of the mobile device to complete performance of a task and is not being received from the user within a predefined time period, at least one form of user notification is generated. The particular form or forms of user notification are defined by a user profile associated with the user. User notifications may comprise visual, audible, and/or vibratory alerts, and different forms of these user notifications may be generated in a sequence. The volume of audible alerts or the period between periodic user notifications may vary over time.

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

Field of the Invention

Embodiments of the invention relate generally to mobile devices andmethods for generating user notifications thereon.

BACKGROUND OF THE INVENTION

When a user wishes to send a message from a mobile device that he or shehas composed, such as an electronic mail (“e-mail”) message for example,the user will typically provide some input to the mobile device throughthe user interface of a messaging application in order to initiate theprocessing of the message for sending. For instance, the user may selecta “send” button or menu option to send the message. Once this selectionis made, users generally expect that unless an error message isgenerated and displayed to them immediately, the message willautomatically be sent with no further input or other user interventionrequired.

When a message is sent by a user that is to be encoded using a securemessaging protocol, such as the Secure Multiple Internet Mail Extensions(“S/MIME”) protocol, or the Pretty Good Privacy™ (PGP) protocol or avariant thereof for example, a number of processing actions may need totake place before the message can actually be sent to its intendeddestination. For example, it may be necessary for the messagingapplication to request an update of a security policy from a policyengine (e.g. as implemented in a PGP Universal Server). This securitypolicy dictates the particular encoding that is to be applied to amessage. As a further example, it may be necessary for the messagingapplication to obtain an S/MIME certificate or a PGP key from a localstore or a remote server before a message is encoded and sent. It mayalso be necessary for the messaging application to verify the status ofa particular S/MIME certificate before the message is encoded and sent.

Should the messaging application encounter any problems when performingthe processing actions for a message or require further input from theuser before it can complete the processing of the message for sending,the mobile device may prompt the user for additional information orprompt the user to make a decision as to what should be done with themessage. For example, if the messaging application is unable to verifythe status of a certain certificate required to encode a message, theuser may be asked to decide whether the message should be sent withoutencoding.

Unfortunately, it may take some time after the user initiates theprocessing of the message for sending before a problem is identified.Meanwhile, the user may have assumed that the message would be sent, andconsequently, the user may no longer be paying attention to the mobiledevice. In particular, the user may have placed the mobile device into abelt holster, in a cradle, or in some other location (e.g. left on adesk), such that the mobile device is left unattended. In those cases,the user may not be aware that additional input is required before themobile device will actually send the message.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of embodiments of the systems and methodsdescribed herein, and to show more clearly how they may be carried intoeffect, reference will be made, by way of example, to the accompanyingdrawings in which:

FIG. 1 is a block diagram of a mobile device in one exampleimplementation;

FIG. 2 is a block diagram of a communication subsystem component of themobile device of FIG. 1;

FIG. 3 is a block diagram of a node of a wireless network;

FIG. 4 is a block diagram illustrating components of a host system inone example configuration; and

FIG. 5 is a flowchart illustrating steps in a method of generating usernotifications associated with tasks pending completion on a mobiledevice, in accordance with a number of example embodiments.

DETAILED DESCRIPTION

Further to the example provided above, if a messaging applicationencounters any problems when performing certain processing actions for amessage that the user has directed the application to send, or if theapplication requires additional input from the user before it cancomplete the processing of the message for sending, it may be necessaryto regain the attention of the user who may have left the mobile deviceunattended.

More generally, whenever a user initiates performance of any task on themobile device that he or she expects to be automatically performedwithout the need for additional input or user intervention, it may benecessary to subsequently regain the attention of the user who may haveleft the mobile device unattended, so that the user can be notified thatadditional input is required before performance of the task can becompleted.

Embodiments described herein relate generally to a device and methods inwhich the user is notified that additional input is required beforeperformance of the task can be completed.

In one broad aspect, there is provided a method of generating usernotifications associated with tasks that are pending completion on amobile device, the method comprising the steps of: receiving input froma user to initiate performance of a task on the mobile device; and whenadditional input is required to complete performance of the task,prompting the user for the additional input, determining if theadditional input is not being received from the user within a predefinedtime period, and generating at least one form of user notification asdefined by a user profile associated with the user, if the additionalinput is not being received from the user within the predefined timeperiod.

These and other aspects and features of various embodiments will bedescribed in greater detail below.

Embodiments described herein make reference to a mobile device. A mobiledevice is a two-way communication device with advanced datacommunication capabilities having the capability to communicate withother computer systems. A mobile device may also include the capabilityfor voice communications. Depending on the functionality provided by amobile device, it may be referred to as a data messaging device, atwo-way pager, a cellular telephone with data messaging capabilities, awireless Internet appliance, or a data communication device (with orwithout telephony capabilities). A mobile device communicates with otherdevices through a network of transceiver stations.

To aid the reader in understanding the structure of a mobile device andhow it communicates with other devices, reference is made to FIGS. 1through 3.

Referring first to FIG. 1, a block diagram of a mobile device in oneexample implementation is shown generally as 100. Mobile device 100comprises a number of components, the controlling component beingmicroprocessor 102. Microprocessor 102 controls the overall operation ofmobile device 100. Communication functions, including data and voicecommunications, are performed through communication subsystem 104.Communication subsystem 104 receives messages from and sends messages toa wireless network 200. In this example implementation of mobile device100, communication subsystem 104 is configured in accordance with theGlobal System for Mobile Communication (GSM) and General Packet RadioServices (GPRS) standards. The GSM/GPRS wireless network is usedworldwide and it is expected that these standards will be supersededeventually by Enhanced Data GSM Environment (EDGE) and Universal MobileTelecommunications Service (UMTS). New standards are still beingdefined, but it is believed that they will have similarities to thenetwork behaviour described herein, and it will also be understood bypersons skilled in the art that the invention is intended to use anyother suitable standards that are developed in the future. The wirelesslink connecting communication subsystem 104 with network 200 representsone or more different Radio Frequency (RF) channels, operating accordingto defined protocols specified for GSM/GPRS communications. With newernetwork protocols, these channels are capable of supporting both circuitswitched voice communications and packet switched data communications.

Although the wireless network associated with mobile device 100 is aGSM/GPRS wireless network in one example implementation of mobile device100, other wireless networks may also be associated with mobile device100 in variant implementations. Different types of wireless networksthat may be employed include, for example, data-centric wirelessnetworks, voice-centric wireless networks, and dual-mode networks thatcan support both voice and data communications over the same physicalbase stations. Combined dual-mode networks include, but are not limitedto, Code Division Multiple Access (CDMA) or CDMA2000 networks, GSM/GPRSnetworks (as mentioned above), and future third-generation (3G) networkslike EDGE and UMTS. Some older examples of data-centric networks includethe Mobitex™ Radio Network and the DataTAC™ Radio Network. Examples ofolder voice-centric data networks include Personal Communication Systems(PCS) networks like GSM and Time Division Multiple Access (TDMA)systems.

Microprocessor 102 also interacts with additional subsystems such as aRandom Access Memory (RAM) 106, flash memory 108, display 110, auxiliaryinput/output (I/O) subsystem 112, serial port 114, keyboard 116, speaker118, microphone 120, short-range communications 122 and other devices124.

Some of the subsystems of mobile device 100 performcommunication-related functions, whereas other subsystems may provide“resident” or on-device functions. By way of example, display 110 andkeyboard 116 may be used for both communication-related functions, suchas entering a text message for transmission over network 200, anddevice-resident functions such as a calculator or task list. Operatingsystem software used by microprocessor 102 is typically stored in apersistent store such as flash memory 108, which may alternatively be aread-only memory (ROM) or similar storage element (not shown). Thoseskilled in the art will appreciate that the operating system, specificdevice applications, or parts thereof, may be temporarily loaded into avolatile store such as RAM 106.

Mobile device 100 may send and receive communication signals overnetwork 200 after required network registration or activation procedureshave been completed. Network access is associated with a subscriber oruser of a mobile device 100. To identify a subscriber, mobile device 100requires a Subscriber Identity Module or “SIM” card 126 to be insertedin a SIM interface 128 in order to communicate with a network. SIM 126is one type of a conventional “smart card” used to identify a subscriberof mobile device 100 and to personalize the mobile device 100, amongother things. Without SIM 126, mobile device 100 is not fullyoperational for communication with network 200. By inserting SIM 126into SIM interface 128, a subscriber can access all subscribed services.Services could include: web browsing and messaging such as e-mail, voicemail, Short Message Service (SMS), and Multimedia Messaging Services(MMS). More advanced services may include: point of sale, field serviceand sales force automation. SIM 126 includes a processor and memory forstoring information. Once SIM 126 is inserted in SIM interface 128, itis coupled to microprocessor 102. In order to identify the subscriber,SIM 126 contains some user parameters such as an International MobileSubscriber Identity (IMSI). An advantage of using SIM 126 is that asubscriber is not necessarily bound by any single physical mobiledevice. SIM 126 may store additional subscriber information for a mobiledevice as well, including datebook (or calendar) information and recentcall information.

Mobile device 100 is a battery-powered device and includes a batteryinterface 132 for receiving one or more rechargeable batteries 130.Battery interface 132 is coupled to a regulator (not shown), whichassists battery 130 in providing power V+ to mobile device 100. Althoughcurrent technology makes use of a battery, future technologies such asmicro fuel cells may provide the power to mobile device 100.

Microprocessor 102, in addition to its operating system functions,enables execution of software applications on mobile device 100. A setof applications that control basic device operations, including data andvoice communication applications, will normally be installed on mobiledevice 100 during its manufacture. Another application that may beloaded onto mobile device 100 would be a personal information manager(PIM). A PIM has functionality to organize and manage data items ofinterest to a subscriber, such as, but not limited to, e-mail, calendarevents, voice mails, appointments, and task items. A PIM application hasthe ability to send and receive data items via wireless network 200. PIMdata items may be seamlessly integrated, synchronized, and updated viawireless network 200 with the mobile device subscriber's correspondingdata items stored and/or associated with a host computer system. Thisfunctionality creates a mirrored host computer on mobile device 100 withrespect to such items. This can be particularly advantageous where thehost computer system is the mobile device subscriber's office computersystem.

Additional applications may also be loaded onto mobile device 100through network 200, auxiliary I/O subsystem 112, serial port 114,short-range communications subsystem 122, or any other suitablesubsystem 124. This flexibility in application installation increasesthe functionality of mobile device 100 and may provide enhancedon-device functions, communication-related functions, or both. Forexample, secure communication applications may enable electroniccommerce functions and other such financial transactions to be performedusing mobile device 100.

Serial port 114 enables a subscriber to set preferences through anexternal device or software application and extends the capabilities ofmobile device 100 by providing for information or software downloads tomobile device 100 other than through a wireless communication network.The alternate download path may, for example, be used to load anencryption key onto mobile device 100 through a direct and thus reliableand trusted connection to provide secure device communication.

Short-range communications subsystem 122 provides for communicationbetween mobile device 100 and different systems or devices, without theuse of network 200. For example, subsystem 122 may include an infrareddevice and associated circuits and components for short-rangecommunication. Examples of short range communication would includestandards developed by the Infrared Data Association (IrDA), Bluetooth,and the 802.11 family of standards developed by IEEE.

In use, a received signal such as a text message, an e-mail message, orweb page download will be processed by communication subsystem 104 andinput to microprocessor 102. Microprocessor 102 will then process thereceived signal for output to display 110 or alternatively to auxiliaryI/O subsystem 112. A subscriber may also compose data items, such ase-mail messages, for example, using keyboard 116 in conjunction withdisplay 110 and possibly auxiliary I/O subsystem 112. Auxiliarysubsystem 112 may include devices such as: a touch screen, mouse, trackball, infrared fingerprint detector, or a roller wheel with dynamicbutton pressing capability. Keyboard 116 is an alphanumeric keyboardand/or telephone-type keypad. A composed item may be transmitted overnetwork 200 through communication subsystem 104.

For voice communications, the overall operation of mobile device 100 issubstantially similar, except that the received signals would be outputto speaker 118, and signals for transmission would be generated bymicrophone 120. Alternative voice or audio I/O subsystems, such as avoice message recording subsystem, may also be implemented on mobiledevice 100. Although voice or audio signal output is accomplishedprimarily through speaker 118, display 110 may also be used to provideadditional information such as the identity of a calling party, durationof a voice call, or other voice call related information.

Referring now to FIG. 2, a block diagram of the communication subsystemcomponent 104 of FIG. 1 is shown. Communication subsystem 104 comprisesa receiver 150, a transmitter 152, one or more embedded or internalantenna elements 154, 156, Local Oscillators (LOs) 158, and a processingmodule such as a Digital Signal Processor (DSP) 160.

The particular design of communication subsystem 104 is dependent uponthe network 200 in which mobile device 100 is intended to operate, thusit should be understood that the design illustrated in FIG. 2 servesonly as one example. Signals received by antenna 154 through network 200are input to receiver 150, which may perform such common receiverfunctions as signal amplification, frequency down conversion, filtering,channel selection, and analog-to-digital (A/D) conversion. A/Dconversion of a received signal allows more complex communicationfunctions such as demodulation and decoding to be performed in DSP 160.In a similar manner, signals to be transmitted are processed, includingmodulation and encoding, by DSP 160. These DSP-processed signals areinput to transmitter 152 for digital-to-analog (D/A) conversion,frequency up conversion, filtering, amplification and transmission overnetwork 200 via antenna 156. DSP 160 not only processes communicationsignals, but also provides for receiver and transmitter control. Forexample, the gains applied to communication signals in receiver 150 andtransmitter 152 may be adaptively controlled through automatic gaincontrol algorithms implemented in DSP 160.

The wireless link between mobile device 100 and a network 200 maycontain one or more different channels, typically different RF channels,and associated protocols used between mobile device 100 and network 200.A RF channel is a limited resource that must be conserved, typically dueto limits in overall bandwidth and limited battery power of mobiledevice 100.

When mobile device 100 is fully operational, transmitter 152 istypically keyed or turned on only when it is sending to network 200 andis otherwise turned off to conserve resources. Similarly, receiver 150is periodically turned off to conserve power until it is needed toreceive signals or information (if at all) during designated timeperiods.

Referring now to FIG. 3, a block diagram of a node of a wireless networkis shown as 202. In practice, network 200 comprises one or more nodes202. Mobile device 100 communicates with a node 202 within wirelessnetwork 200. In the example implementation of FIG. 3, node 202 isconfigured in accordance with General Packet Radio Service (GPRS) andGlobal Systems for Mobile (GSM) technologies. Node 202 includes a basestation controller (BSC) 204 with an associated tower station 206, aPacket Control Unit (PCU) 208 added for GPRS support in GSM, a MobileSwitching Center (MSC) 210, a Home Location Register (HLR) 212, aVisitor Location Registry (VLR) 214, a Serving GPRS Support Node (SGSN)216, a Gateway GPRS Support Node (GGSN) 218, and a Dynamic HostConfiguration Protocol (DHCP) 220. This list of components is not meantto be an exhaustive list of the components of every node 202 within aGSM/GPRS network, but rather a list of components that are commonly usedin communications through network 200.

In a GSM network, MSC 210 is coupled to BSC 204 and to a landlinenetwork, such as a Public Switched Telephone Network (PSTN) 222 tosatisfy circuit switched requirements. The connection through PCU 208,SGSN 216 and GGSN 218 to the public or private network (Internet) 224(also referred to herein generally as a shared network infrastructure)represents the data path for GPRS capable mobile devices. In a GSMnetwork extended with GPRS capabilities, BSC 204 also contains a PacketControl Unit (PCU) 208 that connects to SGSN 216 to controlsegmentation, radio channel allocation and to satisfy packet switchedrequirements. To track mobile device location and availability for bothcircuit switched and packet switched management, HLR 212 is sharedbetween MSC 210 and SGSN 216. Access to VLR 214 is controlled by MSC210.

Station 206 is a fixed transceiver station. Station 206 and BSC 204together form the fixed transceiver equipment. The fixed transceiverequipment provides wireless network coverage for a particular coveragearea commonly referred to as a “cell”. The fixed transceiver equipmenttransmits communication signals to and receives communication signalsfrom mobile devices within its cell via station 206. The fixedtransceiver equipment normally performs such functions as modulation andpossibly encoding and/or encryption of signals to be transmitted to themobile device in accordance with particular, usually predetermined,communication protocols and parameters, under control of its controller.The fixed transceiver equipment similarly demodulates and possiblydecodes and decrypts, if necessary, any communication signals receivedfrom mobile device 100 within its cell. Communication protocols andparameters may vary between different nodes. For example, one node mayemploy a different modulation scheme and operate at differentfrequencies than other nodes.

For all mobile devices 100 registered with a specific network, permanentconfiguration data such as a user profile is stored in HLR 212. HLR 212also contains location information for each registered mobile device andcan be queried to determine the current location of a mobile device. MSC210 is responsible for a group of location areas and stores the data ofthe mobile devices currently in its area of responsibility in VLR 214.Further VLR 214 also contains information on mobile devices that arevisiting other networks. The information in VLR 214 includes part of thepermanent mobile device data transmitted from HLR 212 to VLR 214 forfaster access. By moving additional information from a remote HLR 212node to VLR 214, the amount of traffic between these nodes can bereduced so that voice and data services can be provided with fasterresponse times and at the same time requiring less use of computingresources.

SGSN 216 and GGSN 218 are elements added for GPRS support; namely packetswitched data support, within GSM. SGSN 216 and MSC 210 have similarresponsibilities within wireless network 200 by keeping track of thelocation of each mobile device 100. SGSN 216 also performs securityfunctions and access control for data traffic on network 200. GGSN 218provides internetworking connections with external packet switchednetworks and connects to one or more SGSN's 216 via an Internet Protocol(IP) backbone network operated within the network 200. During normaloperations, a given mobile device 100 must perform a “GPRS Attach” toacquire an IP address and to access data services. This requirement isnot present in circuit switched voice channels as Integrated ServicesDigital Network (ISDN) addresses are used for routing incoming andoutgoing calls. Currently, all GPRS capable networks use private,dynamically assigned IP addresses, thus requiring a DHCP server 220connected to the GGSN 218. There are many mechanisms for dynamic IPassignment, including using a combination of a Remote AuthenticationDial-In User Service (RADIUS) server and DHCP server. Once the GPRSAttach is complete, a logical connection is established from a mobiledevice 100, through PCU 208, and SGSN 216 to an Access Point Node (APN)within GGSN 218. The APN represents a logical end of an IP tunnel thatcan either access direct Internet compatible services or private networkconnections. The APN also represents a security mechanism for network200, insofar as each mobile device 100 must be assigned to one or moreAPNs and mobile devices 100 cannot exchange data without firstperforming a GPRS Attach to an APN that it has been authorized to use.The APN may be considered to be similar to an Internet domain name suchas “myconnection.wireless.com”.

Once the GPRS Attach is complete, a tunnel is created and all traffic isexchanged within standard IP packets using any protocol that can besupported in IP packets. This includes tunneling methods such as IP overIP as in the case with some IPSecurity (Ipsec) connections used withVirtual Private Networks (VPN). These tunnels are also referred to asPacket Data Protocol (PDP) Contexts and there are a limited number ofthese available in the network 200. To maximize use of the PDP Contexts,network 200 will run an idle timer for each PDP Context to determine ifthere is a lack of activity. When a mobile device 100 is not using itsPDP Context, the PDP Context can be deallocated and the IP addressreturned to the IP address pool managed by DHCP server 220.

Referring now to FIG. 4, a block diagram illustrating components of ahost system in one example configuration is shown. Host system 250 willtypically be a corporate office or other local area network (LAN), butmay instead be a home office computer or some other private system, forexample, in variant implementations. In this example shown in FIG. 4,host system 250 is depicted as a LAN of an organization to which a userof mobile device 100 belongs.

LAN 250 comprises a number of network components connected to each otherby LAN connections 260. For instance, a user's desktop computing device(“desktop computer”) 262 a with an accompanying cradle 264 for theuser's mobile device 100 is situated on LAN 250. Cradle 264 for mobiledevice 100 may be coupled to computer 262 a by a serial or a UniversalSerial Bus (USB) connection, for example. Other user computers 262 b arealso situated on LAN 250, and each may or may not be equipped with anaccompanying cradle 264 for a mobile device. Cradle 264 facilitates theloading of information (e.g. PIM data, private symmetric encryption keysto facilitate secure communications between mobile device 100 and LAN250) from user computer 262 a to mobile device 100, and may beparticularly useful for bulk information updates often performed ininitializing mobile device 100 for use. The information downloaded tomobile device 100 may include S/MIME certificates or PGP keys used inthe exchange of messages. The process of downloading information from auser's desktop computer 262 a to the user's mobile device 100 may alsobe referred to as synchronization.

It will be understood by persons skilled in the art that user computers262 a, 262 b will typically be also connected to other peripheraldevices not explicitly shown in FIG. 4. Furthermore, only a subset ofnetwork components of LAN 250 are shown in FIG. 4 for ease ofexposition, and it will be understood by persons skilled in the art thatLAN 250 will comprise additional components not explicitly shown in FIG.4, for this example configuration. More generally, LAN 250 may representa smaller part of a larger network [not shown] of the organization, andmay comprise different components and/or be arranged in differenttopologies than that shown in the example of FIG. 4.

In this example, mobile device 100 communicates with LAN 250 through anode 202 of wireless network 200 and a shared network infrastructure 224such as a service provider network or the public Internet. Access to LAN250 may be provided through one or more routers [not shown], andcomputing devices of LAN 250 may operate from behind a firewall or proxyserver 266.

In a variant implementation, LAN 250 comprises a wireless VPN router[not shown] to facilitate data exchange between the LAN 250 and mobiledevice 100. The concept of a wireless VPN router is new in the wirelessindustry and implies that a VPN connection can be established directlythrough a specific wireless network to mobile device 100. Thepossibility of using a wireless VPN router has only recently beenavailable and could be used when the new Internet Protocol (IP) Version6 (IPV6) arrives into IP-based wireless networks. This new protocol willprovide enough IP addresses to dedicate an IP address to every mobiledevice, making it possible to push information to a mobile device at anytime. An advantage of using a wireless VPN router is that it could be anoff-the-shelf VPN component, not requiring a separate wireless gatewayand separate wireless infrastructure to be used. A VPN connection wouldpreferably be a Transmission Control Protocol (TCP)/IP or User DatagramProtocol (UDP)/IP connection to deliver the messages directly to mobiledevice 100 in this variant implementation.

Messages intended for a user of mobile device 100 are initially receivedby a message server 268 of LAN 250. Such messages may originate from anyof a number of sources. For instance, a message may have been sent by asender from a computer 262 b within LAN 250, from a different mobiledevice [not shown] connected to wireless network 200 or to a differentwireless network, or from a different computing device or other devicecapable of sending messages, via the shared network infrastructure 224,and possibly through an application service provider (ASP) or Internetservice provider (ISP), for example.

Message server 268 typically acts as the primary interface for theexchange of messages, particularly e-mail messages, within theorganization and over the shared network infrastructure 224. Each userin the organization that has been set up to send and receive messages istypically associated with a user account managed by message server 268.One example of a message server 268 is a Microsoft Exchange™ Server. Insome implementations, LAN 250 may comprise multiple message servers 268.Message server 268 may also be adapted to provide additional functionsbeyond message management, including the management of data associatedwith calendars and task lists, for example.

When messages are received by message server 268, they are typicallystored in a message store [not explicitly shown], from which messagescan be subsequently retrieved and delivered to users. For instance, ane-mail client application operating on a user's computer 262 a mayrequest the e-mail messages associated with that user's account storedon message server 268. These messages would then typically be retrievedfrom message server 268 and stored locally on computer 262 a.

When operating mobile device 100, the user may wish to have e-mailmessages retrieved for delivery to the handheld. An e-mail clientapplication operating on mobile device 100 may also request messagesassociated with the user's account from message server 268. The e-mailclient may be configured (either by the user or by an administrator,possibly in accordance with an organization's information technology(IT) policy) to make this request at the direction of the user, at somepre-defined time interval, or upon the occurrence of some pre-definedevent. In some implementations, mobile device 100 is assigned its owne-mail address, and messages addressed specifically to mobile device 100are automatically redirected to mobile device 100 as they are receivedby message server 268.

To facilitate the wireless communication of messages and message-relateddata between mobile device 100 and components of LAN 250, a number ofwireless communications support components 270 may be provided. In thisexample implementation, wireless communications support components 270comprise a message management server 272, for example. Messagemanagement server 272 is used to specifically provide support for themanagement of messages, such as e-mail messages, that are to be handledby mobile devices. Generally, while messages are still stored on messageserver 268, message management server 272 can be used to control when,if, and how messages should be sent to mobile device 100. Messagemanagement server 272 also facilitates the handling of messages composedon mobile device 100, which are sent to message server 268 forsubsequent delivery.

For example, message management server 272 may: monitor the user's“mailbox” (e.g. the message store associated with the user's account onmessage server 268) for new e-mail messages; apply user-definablefilters to new messages to determine if and how the messages will berelayed to the user's mobile device 100; compress and encrypt newmessages (e.g. using an encryption technique such as Data EncryptionStandard (DES) or Triple DES) and push them to mobile device 100 via theshared network infrastructure 224 and wireless network 200; and receivemessages composed on mobile device 100 (e.g. encrypted using TripleDES), decrypt and decompress the composed messages, re-format thecomposed messages if desired so that they will appear to have originatedfrom the user's computer 262 a, and re-route the composed messages tomessage server 268 for delivery.

Certain properties or restrictions associated with messages that are tobe sent from and/or received by mobile device 100 can be defined (e.g.by an administrator in accordance with IT policy) and enforced bymessage management server 272. These may include whether mobile device100 may receive encrypted and/or signed messages, minimum encryption keysizes, whether outgoing messages must be encrypted and/or signed, andwhether copies of all secure messages sent from mobile device 100 are tobe sent to a pre-defined copy address, for example.

Message management server 272 may also be adapted to provide othercontrol functions, such as only pushing certain message information orpre-defined portions (e.g. “blocks”) of a message stored on messageserver 268 to mobile device 100. For example, when a message isinitially retrieved by mobile device 100 from message server 268,message management server 272 is adapted to push only the first part ofa message to mobile device 100, with the part being of a pre-definedsize (e.g. 2 KB). The user can then request more of the message, to bedelivered in similar-sized blocks by message management server 272 tomobile device 100, possibly up to a maximum pre-defined message size.

Accordingly, message management server 272 facilitates better controlover the type of data and the amount of data that is communicated tomobile device 100, and can help to minimize potential waste of bandwidthor other resources.

It will be understood by persons skilled in the art that messagemanagement server 272 need not be implemented on a separate physicalserver in LAN 250 or other network. For example, some or all of thefunctions associated with message management server 272 may beintegrated with message server 268, or some other server in LAN 250.Furthermore, LAN 250 may comprise multiple message management servers272, particularly in variant implementations where a large number ofmobile devices need to be supported.

Certificates may be used in the processing of encoded messages, such ase-mail messages, that are encrypted and/or signed, in accordance withcertain secure messaging protocols. While Simple Mail Transfer Protocol(SMTP), RFC822 headers, and Multipurpose Internet Mail Extensions (MIME)body parts may be used to define the format of a typical e-mail messagenot requiring encoding, Secure/MIME (S/MIME), a version of the MIMEprotocol, may be used in the communication of encoded messages (i.e. insecure messaging applications). S/MIME enables end-to-end authenticationand confidentiality, and provides data integrity and privacy from thetime an originator of a message sends a message until it is decoded andread by the message recipient. Other standards and protocols may beemployed to facilitate secure message communication, such as Pretty GoodPrivacy™ (PGP) and variants of PGP such as OpenPGP, for example. It willbe understood that where reference is generally made to “PGP” herein,the term is intended to encompass any of a number of variantimplementations based on the more general PGP scheme.

Secure messaging protocols such as S/MIME and PGP-based protocols relyon public and private encryption keys to provide confidentiality andintegrity. Data encoded using a private key of a private key/public keypair can only be decoded using the corresponding public key of the pair,and data encoded using a public key of a private key/public key pair canonly be decoded using the corresponding private key of the pair. It isintended that private key information never be made public, whereaspublic key information is shared.

For example, if a sender wishes to send a message to a recipient inencrypted form, the recipient's public key is used to encrypt a message,which can then be decrypted only using the recipient's private key.Alternatively, in some encoding techniques, a one-time session key isgenerated and used to encrypt the body of a message, typically with asymmetric encryption technique (e.g. Triple DES). The session key isthen encrypted using the recipient's public key (e.g. with a public keyencryption algorithm such as RSA), which can then be decrypted onlyusing the recipient's private key. The decrypted session key can then beused to decrypt the message body. The message header may be used tospecify the particular encryption scheme that must be used to decryptthe message. Other encryption techniques based on public keycryptography may be used in variant implementations. However, in each ofthese cases, only the recipient's private key may be used to facilitatesuccessful decryption of the message, and in this way, theconfidentiality of messages can be maintained.

As a further example, a sender may sign a message using a digitalsignature. A digital signature is a digest of the message (e.g. a hashof the message) encoded using the sender's private key, which can thenbe appended to the outgoing message. To verify the digital signature ofthe message when received, the recipient uses the same technique as thesender (e.g. using the same standard hash algorithm) to obtain a digestof the received message. The recipient also uses the sender's public keyto decode the digital signature, in order to obtain what should be amatching digest for the received message. If the digests of the receivedmessage do not match, this suggests that either the message content waschanged during transport and/or the message did not originate from thesender whose public key was used for verification. Digital signaturealgorithms are designed in such a way that only someone with knowledgeof the sender's private key should be able to encode a signature thatthe recipient will decode correctly using the sender's public key.Therefore, by verifying a digital signature in this way, authenticationof the sender and message integrity can be maintained.

An encoded message may be encrypted, signed, or both encrypted andsigned. In S/MIME, the authenticity of public keys used in theseoperations is validated using certificates. A certificate is a digitaldocument issued by a certificate authority (CA). Certificates are usedto authenticate the association between users and their public keys, andessentially, provides a level of trust in the authenticity of the users'public keys. Certificates contain information about the certificateholder, with certificate contents typically formatted in accordance withan accepted standard (e.g. X.509). The certificates are typicallydigitally signed by the certificate authority.

In PGP-based systems, a PGP key is used, which is like an S/MIMEcertificate in that it contains public information including a publickey and information on the key holder or owner. Unlike S/MIMEcertificates, however, PGP keys are not generally issued by acertificate authority, and the level of trust in the authenticity of aPGP key typically requires verifying that a trusted individual hasvouched for the authenticity of a given PGP key.

For the purposes of the specification and in the claims, the term“certificate” is used generally to describe a construct used to providepublic keys for encoding and decoding messages and possibly informationon the key holder, and may be deemed to include what is generally knownas a “PGP key” and other similar constructs.

Standard e-mail security protocols typically facilitate secure messagetransmission between non-mobile computing devices (e.g. computers 262 a,262 b of FIG. 4; remote desktop devices). In order that signed messagesreceived from senders may be read from mobile device 100 and thatencrypted messages be sent from mobile device 100, mobile device 100 isadapted to store public keys (e.g. in S/MIME certificates, PGP keys) ofother individuals. Keys stored on a user's computer 262 a will typicallybe downloaded from computer 262 a to mobile device 100 through cradle264, for example.

Mobile device 100 may also be adapted to store the private key of thepublic key/private key pair associated with the user, so that the userof mobile device 100 can sign outgoing messages composed on mobiledevice 100, and decrypt messages sent to the user encrypted with theuser's public key. The private key may be downloaded to mobile device100 from the user's computer 262 a through cradle 264, for example. Theprivate key is preferably exchanged between the computer 262 a andmobile device 100 so that the user may share one identity and one methodfor accessing messages.

User computers 262 a, 262 b can obtain S/MIME certificates and PGP keysfrom a number of sources, for storage on computers 262 a, 262 b and/ormobile devices (e.g. mobile device 100). These certificate sources maybe private (e.g. dedicated for use within an organization) or public,may reside locally or remotely, and may be accessible from within anorganization's private network or through the Internet, for example. Inthe example shown in FIG. 4, multiple public key infrastructure (PKI)servers 280 associated with the organization reside on LAN 250. PKIservers 280 include a CA server 282 that may be used for issuing S/MIMEcertificates, a Lightweight Directory Access Protocol (LDAP) server 284that may be used to search for and download S/MIME certificates and/orPGP keys (e.g. for individuals within the organization), and an OnlineCertificate Status Protocol (OCSP) server 286 that may be used to verifythe revocation status of S/MIME certificates, for example.

Certificates and/or PGP keys may be retrieved from LDAP server 284 by auser computer 262 a, for example, to be downloaded to mobile device 100via cradle 264. However, in a variant implementation, LDAP server 284may be accessed directly (i.e. “over the air” in this context) by mobiledevice 100, and mobile device 100 may search for and retrieve individualcertificates and PGP keys through a mobile data server 288. Similarly,mobile data server 288 may be adapted to allow mobile device 100 todirectly query OCSP server 286 to verify the revocation status of S/MIMEcertificates.

In variant implementations, only selected PKI servers 280 may be madeaccessible to mobile devices (e.g. allowing certificates to bedownloaded only from a user's computer 262 a, 262 b, while allowing therevocation status of certificates to be checked from mobile device 100).

In variant implementations, certain PKI servers 280 may be madeaccessible only to mobile devices registered to particular users, asspecified by an IT administrator, possibly in accordance with an ITpolicy, for example.

Other sources of S/MIME certificates and PGP keys [not shown] mayinclude a Windows certificate or key store, another secure certificateor key store on or outside LAN 250, and smart cards, for example.

In the example shown in FIG. 4, a policy engine 290 resides in LAN 250.The policy engine 290 may be provided by way of a PGP Universal Serverdeveloped by PGP Corporation. This is only one example. The policyengine may be implemented in some other device or construct other than aPGP Universal Server, and may be applied in the context of protocolsother than PGP (e.g. in an S/MIME policy engine).

A PGP Universal Server 290 is adapted to communicate with a user'sdesktop computer (e.g. 262 a) and the user's mobile device (e.g. 100 viamessage management server 272), and may be further adapted to encryptmessages and enforce compliance of security requirements with respect tomessages being sent by the user, based on security policies establishedby an administrator, for example. The placement of PGP Universal Server290 in LAN 250 as shown in FIG. 4 is provided by way of example only,and other placements and configurations are possible. Depending on theplacement of the PGP Universal Server 290 and the particularconfiguration of LAN 250 in which PGP Universal Server 290 may beemployed, the level of control over processed messages that are subjectto security encoding, and in particular, over messages being sent by auser may vary.

For example, PGP Universal Server 290 may be adapted to directly processall outgoing messages (i.e. messages being sent by the user from theuser's desktop computer, mobile device, or other computing device to oneor more intended recipients), where it will make decisions on whichmessages to encrypt and/or sign, if at all, in accordance with policiesdefined on the PGP Universal Server 290 as configured by theadministrator. If a security policy dictates that a message about to besent by the user to a particular domain or pertaining to a particularsubject is to be encrypted and signed using PGP for example, the PGPUniversal Server 290 may itself encrypt and sign the message beforetransmission.

Alternatively, the user, through a PGP-enabled messaging application onthe user's computing device that communicates with PGP Universal Server290 for example, may download security policy data from the PGPUniversal Server 290 to the user's computing device. The user or theapplication may then be directed to encrypt and sign the message beforetransmission, based on the security policy data obtained.

Accordingly, PGP Universal Server 290 provides the ability to enforcecentralized policy based on domains and other mechanisms.

The PGP Universal Server 290 may also be adapted to store, validate, andotherwise manage PGP keys, and to retrieve PGP keys from remote keystores when the keys are required to encode (e.g. encrypt and/or sign)messages. Where requested by a user or application, PGP Universal Server290 may also provide stored or retrieved PGP keys to the user as needed.

By adopting the use of a policy engine such as that implemented by a PGPUniversal Server 290 as described herein by way of example, much of theburden associated with processing secure messages (e.g. e-mail), and inparticular, with deciding what messages are to be sent securely and whatsecurity encoding should apply on a case-by-case basis, can betransferred to the policy engine.

Referring now to FIG. 5, a flowchart illustrating steps in a method ofgenerating user notifications associated with tasks pending completionon a mobile device, in accordance with a number of example embodiments,is shown generally as 300.

Steps of method 300 are performed by an application executing andresiding on the mobile device (e.g. mobile device 100 of FIG. 4). Theapplication may be an e-mail or other messaging application, anotherapplication coupled to or otherwise integrated with the e-mail or othermessaging application (e.g. an add-on component providing the requisitefunctionality), or some other application programmed to perform suchsteps.

In embodiments of method 300, the user is notified that additional inputis required before performance of a task can be completed. Generally,whenever a user initiates performance of a task on the mobile devicethat he or she expects to be automatically performed without the needfor additional input or user intervention, it may be necessary tosubsequently regain the attention of the user who may have left themobile device unattended.

At step 310, input to initiate performance of a task on a mobile deviceis received from a user of the mobile device.

By way of example, in one embodiment, the task comprises processing amessage (e.g. an e-mail message) composed by the user. The user may wishto send the message securely (e.g. encrypted and/or signed), or amessage encoding may be suggested or enforced by a policy engine (e.g.as implemented in a PGP Universal Server 290 of FIG. 4). The user maywish to have the message sent to one or more recipients, and may providethe messaging application with a direction that the message is to besent, by selecting a “send” button or menu option, for example. When thedirection is received by the messaging application, processing of themessage for sending is initiated.

Typically, unless an error is detected by the messaging applicationimmediately after the direction is received and the user is notified ofthe error, the user may assume that the message will be sent without theneed for additional input or user intervention. Subsequently, the usermay leave the mobile device unattended in a holster (e.g. a beltholster), in a cradle (e.g. cradle 264 of FIG. 4), or in some otherlocation (e.g. desk, pocket, bag, etc.), for example.

At step 320, if in the process of performing the task, additional inputis required to complete performance of the task initiated at step 310,the user is prompted for the additional input.

With reference to the above-mentioned example, consider the situationwhere a message composed by the user is to be encrypted and sent to oneor more recipients. The certificate (which may, for example, be a S/MIMEcertificate or a PGP key) of each recipient to which the message is tobe encrypted is required. Therefore, the processing of the messagecomposed by the user will require a number of actions to be performed,which may include searching for and retrieving the requisitecertificate(s) from a local or remote certificate/key store orcertificate server (e.g. LDAP server 284 of FIG. 4), and verifying thestatus of the certificate (which may include, for example, verifyingcertificate validity/expiry, revocation status, key strength, and/ortrust status), for example.

Processing of the message may also require that a correct password beobtained from the user as input, as may be required when an attempt toaccess a certificate in certain protected certificate/key stores on themobile device is made.

Processing of the message may comprise performing actions that requireadditional input from the user before the processing of the message forsending can be completed other than those described above, by way ofexample.

The additional input required to complete the processing of the messagemay be in the form of input indicating the response to a question thathas been posed to a user. For example, in processing the message, therequisite certificate associated with a potential recipient may bedetermined to be “not trusted”. The messaging application can prompt theuser for input indicating whether or not the user still wishes toproceed with sending the message, despite the fact that a certificatethat is not trusted would be used to encrypt the message. As a furtherexample, in processing the message, multiple certificates for a givenpotential recipient may have been located, any of which might be used toencrypt the message. The messaging application may need to prompt theuser for additional input indicating which of the located certificatesshould be used to encrypt the message.

When the user is prompted for additional input at step 320, themessaging application is adapted to wait for a response from the user.Progress in the performance of the task (e.g. further processing of themessage) may be temporarily suspended until the additional input isreceived from the user. Alternatively, other actions may be completed inthe background while a response from the user is pending.

If the user is operating the mobile device and notices the prompt, theuser may begin to provide the required additional input immediately.However, if the user is not operating the device and has left the mobiledevice unattended, the user may not notice the prompt. The lattersituation may be more likely to occur when the messaging application isunable to determine that additional input is required immediately afterthe user initiates the task.

For example, when a message is to be encoded using PGP in accordancewith a security policy, and where security policy data must first bedownloaded from a policy engine (e.g. as implemented in a PGP UniversalServer 290 of FIG. 4), there may be a delay between the time the userdirected the message to be sent, and the time when the security policydata is retrieved. The reporting of problems arising in the retrieval ofsecurity policy data, or of any problems that may arise from actions tobe performed after the retrieval of such data, may consequently bedelayed. If additional input is required from the user in order todetermine how these problems should be overcome, the user is not likelyto be prompted for the additional input immediately after the userdirects the message to be sent. By the time the messaging applicationdetermines that additional input is required, the user may have sinceleft the mobile device unattended.

At step 330, a determination is made as to whether additional input isnot being received from the user within a predefined time period. Thepredefined time period establishes how long the messaging applicationwill wait before proceeding to generate user notifications if the useris not in the process of responding to the prompt. For example, once theuser is prompted for the additional input at step 320 (e.g. via a windowappearing in a display of the mobile device), the messaging applicationmay allow 30 seconds (or some other length of time) to elapse. If theuser has not attempted to respond to the prompt in this period, usernotifications will then be generated (step 340).

The predefined time period may be fixed by the messaging application, orit may be configurable by the user by modifying a setting in devicepreferences or in a user profile, for example. As a further example, thepredefined time period may be set in accordance with an IT policygoverning use of the mobile device.

If the additional input is received or is at least in the process ofbeing received from the user within the predefined time period (e.g. theuser may be scrolling through a number of selections or entering data onthe keyboard, and therefore, is in the process of responding to theprompt and need not be further notified), then the flow of method stepsproceeds to step 350, wherein progress in the performance of the taskcan continue upon receipt of the additional input.

However, if the additional input is not being received from the userwithin the predefined time period, then it is likely that the user is nolonger attending to or otherwise paying attention to the device.Meanwhile, completion of the task initiated at step 310 remains pending.

Accordingly, at step 340, at least one form of user notification isgenerated, in order to regain the attention of the user so that the usercan respond to the prompt for additional input.

The at least one form of user notification generated at step 340 maycontinue to be generated until the additional input is being received bythe user (i.e. the user begins to respond to the prompt).

The messaging application may also be adapted to generate the at leastone form of user notification until a second predefined time period haselapsed, after which completion of the task may remain pending, orperformance of the task, cancelled. For example, if after two minutes(or some other period of time) the user has still not responded to theprompt, it may be that the user is away from the mobile device and isnot receiving the notifications. The generation of notifications may besuspended temporarily and subsequently continued at a later time, orperformance of the task may be cancelled altogether.

The second predefined time period may be fixed by the messagingapplication, or it may be configurable by the user by modifying asetting in device preferences or in a user profile, for example. As afurther example, the second predefined time period may be set inaccordance with an IT policy governing use of the mobile device.

The at least one form of user notification is generated at step 340 asdefined by a user profile associated with the user. Accordingly, aflexible notification system tied to a user's profile is provided. Forexample, a user profile may define certain alert settings, associatedwith different environments or desired privacy levels (e.g. “Quiet”mode, “Outdoors” mode, etc.). The forms of user notification to begenerated at step 340 are configured to be dependent on the user profileand the alert setting currently enabled by the user.

In one embodiment, the at least one form of user notification generatedat step 340 is based on a state of the mobile device. For example,different forms of user notification may be generated when the mobiledevice is in a cradle (e.g. cradle 264 of FIG. 4), when the mobiledevice is in a holster, and when the mobile device is neither in acradle nor in a holster.

A number of different forms of user notification may be generated invarious embodiments. One form of a user notification that may beemployed is a visual alert. A flashing LED indicator on the mobiledevice may provide the visual alert, for example. Another form of a usernotification that may be employed is an audible alert. The audible alertmay be provided by a “beep” noise, an audio tone, or a musical tone, forexample. Another form of a user notification that may be employed is avibratory alert. The vibratory alert will cause the mobile device tophysically vibrate. Other forms of user notification may be employed invariant embodiments.

Furthermore, successively generated alerts may vary over time. Forinstance, the color or flashing rate of a visual alert may be varied.Audible alerts may vary in volume (e.g. the volume of audible alerts mayescalate over time). The force with which a mobile device vibrates maybe varied.

In at least one embodiment, the at least one form of user notificationgenerated at step 340 is generated periodically. For example, an audiblealert (e.g. “beep”) may be generated every two seconds (or some otherperiod). Furthermore, the period at which user notifications aregenerated may also vary. For example, an audible alert may initially begenerated every 10 seconds (or some other period) over a certain lengthof time, with subsequent alerts being generated at a faster rate, untilan audible alert is generated every second (or some other period).

In one embodiment, the at least one form of user notification generatedat step 340 comprises multiple forms of user notification that are to begenerated in sequence. Put another way, the user profile may becustomized such that the user notifications change in type over time.For example, when user notifications are to be generated at step 340, anumber of visual alerts may first be generated, followed by a number ofvibratory alerts, and finally followed by a number of audible alerts.This represents a sequence in which the noise created by each of thedifferent forms of user notification escalates over time.

It will be understood that some or all of the features of the variousembodiments described above may be combined in a given implementation.For example, when the additional input is not being received from theuser within a predefined time period, an LED indicator may first beflashed every few seconds for 15 minutes, then the mobile device may bevibrated every minute for 15 minutes. This may be followed by theemitting of a “beep” every few seconds for 5 minutes, which may alsoincrease in volume over this period. The rate at which any of thesealerts are generated may also be escalated over the indicated periods,for example. This sequence may also be modified depending on the stateof the mobile device (e.g. whether the mobile device is in a holster,whether the mobile device is in a cradle, etc.).

As noted above, user notifications may be generated at step 340 untilthe additional input is received or is in the process of being receivedfrom the user, wherein the flow of method steps will then proceed tostep 350 at which progress in the performance of the task can continueupon receipt of the additional input. Alternatively, the usernotifications may be generated until a second predefined time period haselapsed, after which completion of the task may remain pending orperformance of the task may be cancelled [step not shown].

Although features of some of the embodiments of method 300 have beendescribed primarily with respect to tasks comprising the processing ofmessages composed by a user for sending to one or more recipients, thedescribed features may also be applicable in respect of other tasks, invariant embodiments.

For example, in a variant embodiment, the task comprises searchingmessages. The user may initiate a search on the mobile device for amessage stored in one or more message folders, or for specific text in amessage (e.g. text in the body of the message, text in a sender's e-mailaddress identified in the header of the message, text in a recipient'se-mail address identified in the header of the message, text in thesubject of a message, etc.), by providing one or more search terms andpossibly selecting a search button or menu selection. While the searchis being performed, the messaging application may encounter an encryptedmessage to which access is required, for example. In that case, it maybe necessary to obtain the requisite password from the user before dataof the encrypted message can be decrypted and accessed for searchingpurposes. The search cannot be completed until the user provides therequisite password as additional input, and the search may potentiallybe suspended until the user provides the requisite password asadditional input.

The steps of the methods described herein may be provided as executablesoftware instructions stored on computer-readable media, which mayinclude transmission-type media.

The invention has been described with regard to a number of embodiments.However, it will be understood by persons skilled in the art that othervariants and modifications may be made without departing from the scopeof the invention as defined in the claims appended hereto.

1. A method of generating user notifications associated with tasks that are pending completion on a mobile device, the method comprising the steps of: receiving input from a user to initiate performance of a task on the mobile device; and when additional input is required to complete performance of the task, prompting the user for the additional input, determining if the additional input is not being received from the user within a predefined time period, and generating at least one form of user notification as defined by a user profile associated with the user, if the additional input is not being received from the user within the predefined time period.
 2. The method of claim 1, wherein the at least one form of user notification is generated at the generating step until the additional input is being received from the user.
 3. The method of claim 1, wherein the at least one form of user notification is generated periodically at the generating step.
 4. The method of claim 3, wherein the period at which the at least one form of user notification is generated at the generating step varies.
 5. The method of claim 1, wherein the at least one form of user notification is generated at the generating step until a second predefined time period has elapsed.
 6. The method of claim 1, wherein the user profile defines the at least one form of user notification that is to be generated at the generating step based on a state of the mobile device.
 7. The method of claim 6, wherein the state of the mobile device is a state selected from the following group: the mobile device is in a cradle; the mobile device is in a holster; and the mobile device is neither in a cradle nor in a holster.
 8. The method of claim 1, wherein the at least one form of user notification consists of at least one of the following: a visual alert, an audible alert, and a vibratory alert.
 9. The method of claim 1, wherein at least one form of user notification varies over time.
 10. The method of claim 1, wherein the user profile defines a plurality of forms of user notification that is to be generated in a sequence at the generating step.
 11. The method of claim 1, wherein the task comprises processing a message composed by the user.
 12. The method of claim 11, wherein the input received from the user at the receiving step comprises a direction that the message is to be sent.
 13. The method of claim 11, wherein the processing of the message comprises encoding the message using PGP.
 14. The method of claim 11, wherein the processing of the message comprises encoding the message using S/MIME.
 15. The method of claim 1, wherein the task comprises searching messages.
 16. A computer-readable medium upon which a plurality of instructions are stored, the instructions for performing the steps of the method of claim
 1. 17. A mobile device adapted to perform the steps of the method of claim
 1. 